This project continues to be concerned with studies of the structure and properties of normal and abnormal human hemoglobins. The effect of inositol hexophosphate on nitrosyl derivatives of fetal, A-Ic and H hemoglobins will provide information about the structure of the ligand binding site. Kinetic studies of the intermediates of CO binding to hemoglobin will be continued. Work on the interactions of hemoglobins, liganded and unliganded, with red cell membranes will continue. The structure of three recently detected mutant hemoglobins is being carried out.